Global CMake reorganization:

[~] Automatically tracked dependencies between modules
 [+] Support for optional module dependencies
 [+] Options to choose modules to build
 [~] Removed hardcoded modules lists from OpenCVConfig.cmake, opencv.pc and OpenCV.mk
 [+] Added COMPONENTS support for FIND_PACKAGE(OpenCV)
 [~] haartraining and traincascade are moved outside of modules folder since they aren't the modules

modules/stitching/include/opencv2/stitching/detail/matchers.hpp

@@ -46,7 +46,8 @@
 #include "opencv2/core/core.hpp"
 #include "opencv2/features2d/features2d.hpp"
 
-#ifndef ANDROID
+#include "opencv2/opencv_modules.hpp"
+#ifdef HAVE_OPENCV_GPU
 #include "opencv2/gpu/gpu.hpp"
 #endif
 
@@ -102,7 +103,7 @@ private:
 };
 
 
-#ifndef ANDROID
+#ifdef HAVE_OPENCV_GPU
 class CV_EXPORTS SurfFeaturesFinderGpu : public FeaturesFinder
 {
 public:

modules/stitching/include/opencv2/stitching/detail/seam_finders.hpp

@@ -44,6 +44,7 @@
 #define __OPENCV_STITCHING_SEAM_FINDERS_HPP__
 
 #include "opencv2/core/core.hpp"
+#include "opencv2/opencv_modules.hpp"
 
 namespace cv {
 namespace detail {
@@ -114,7 +115,7 @@ private:
 };
 
 
-#ifndef ANDROID
+#ifdef HAVE_OPENCV_GPU
 class CV_EXPORTS GraphCutSeamFinderGpu : public GraphCutSeamFinderBase, public PairwiseSeamFinder
 {
 public:

modules/stitching/include/opencv2/stitching/detail/warpers.hpp

@@ -45,7 +45,8 @@
 
 #include "opencv2/core/core.hpp"
 #include "opencv2/imgproc/imgproc.hpp"
-#ifndef ANDROID
+#include "opencv2/opencv_modules.hpp"
+#ifdef HAVE_OPENCV_GPU
 # include "opencv2/gpu/gpu.hpp"
 #endif
 
@@ -184,7 +185,7 @@ protected:
 };
 
 
-#ifndef ANDROID
+#ifdef HAVE_OPENCV_GPU
 class CV_EXPORTS PlaneWarperGpu : public PlaneWarper
 {
 public:

modules/stitching/include/opencv2/stitching/warpers.hpp

@@ -76,7 +76,7 @@ public:
 };
 
 
-#ifndef ANDROID
+#ifdef HAVE_OPENCV_GPU
 class PlaneWarperGpu: public WarperCreator
 {
 public: